Broadband access networks serve inter alia to allow subscribers access to IP-based networks, for example to the Internet. Broadband access networks of this type generally comprise a plurality of access multiplexers, also referred to as access nodes (ANs). Subscriber terminals can be connected to the access nodes via subscriber lines. Examples of known access nodes include DSLAMs (digital subscriber line access multiplexers) to which terminals can be connected via digital subscriber lines (DSLs). Analogue and digital telephones are in this case connected by means of a subscriber-side network termination and computers by means of a DSL modem to the digital subscriber line via a splitter. A splitter, which supplies voice signals to a conventional telephone network and broadband data to the Internet, is, in turn, arranged in the DSLAM. However, access networks of this type do not allow voice signals to be transmitted via the Internet.
In addition, there are solution approaches based on the H.248 Gateway Control Protocol standardised by the ITU. This protocol controls the transmission of voice and signalling data via a media gateway which converts voice signals into VoIP signals. However, the existing solutions do not allow the use of conventional analogue or digital telephones, such as for example ISDN telephones, in order to be able to transmit and receive VoIP signals at the access node via the Internet.